The vet wanted to keep him for a least a couple more hours to make sure he wakes up okay and everything is moving as it should, but she wants him to be able to come home before the day is out. Being in a vet's office with all those scary dogs and cats (especially when you're not used to them) is stressful, and she'd rather having him resting at home.

I'm so glad he got through the surgery ok and hope he's up and about soon. Henry seems like a tough old man. Hope he has a quick and uneventful recovery.

About the Critical Care, IMHO I doubt it would make things worse. I feel like pigs that get stones are really predisposed to them, so while diet definitely plays a part, if you need the Critical Care for his recovery (unless you've heard anything different about any danger with stone pigs) I'd go for it.